Air cleaner for attachment to paint booth doors



c. L. LEEPER 3,370,404 AIR CLEANER FOR ATTACHMENT TO PAINT BOOTH DOORSFeb. 27, 1968 Filed March 20, 1967 6? BY Q ORNEY United States Patent3,370,404 AIR CLEANER FOR ATTACHMENT T0 PAINT BOOTH DOORS Charles LeroyLeeper, 3224 Bonnie Drive, Fort Worth, Tex. 76116 Filed Mar. 20, 1967,Ser. No. 624,257 1 Claim. (Cl. 55-233) ABSTRACT OF THE DISCLGSURE Alight weight, compact air cleaning and conditioning unit for attachmentto the outside of one of the doors of a paint booth of a type which iscommonly used for painting automobiles, for example, and having filterpanels therein through which air is drawn, usually by means of anexhaust fan at the opposite end of the booth.

According to the invention the incoming air is thoroughly cleaned andconditioned, before passing through the filter panels, to improve thequality of the work, to safeguard the health and comfort of personsworking in the booth, and to increase the useful life of the filterpanels.

This invention relates to an air cleaner for attachment to paint boothdoors, and it concerns more particularly a light weight, compact aircleaning and conditioning unit for attachment to the outside of one ofthe doors of a paint booth of a type which is commonly used for paintingautomobiles, for example, as hereinafter described.

Commercial paint booths for the painting of automobiles are ordinarilyprefabricated according to standard specifications, and a pair of doorsare usually provided at one end of the booth for driving an automobilein or out, as desired.

The doors of such paint booths commonly have filter panels thereinwhereby air which is drawn into the booth through the door, in theclosed position thereof, as by means of an exhaust fan at the oppositeend of the booth, may be substantially cleaned. The combined area of thefilter panels may approach the area of the door.

Skilled painters are well aware that in order to produce a qualityfinish, as in painting automobiles, for example, it is necessary tofully protect the work, during painting, against dust which isordinarily present in atmospheric air. Even slight amounts of dust mayspoil a paint job, and for best results complete protection against dustmust be provided.

In use the filter panels which are now incorporated in paint boothdoors, as above described, are only partly effective for the purposeintended, and it has been found that there is a need for more efficientmeans for providing a dust free environment inside a paint booth.

The air cleaning and conditioning unit of the invention is applied tothe outside of a paint booth door, in opposing relation to the filterpanels and in fluid communication therewith.

The air cleaning and conditioning unit of the invention, which ispositioned upstream relative to the filter panels, thoroughly cleans andconditions the incoming air, before it passes through the filter panels,and improves the quality of the work by positively preventing thepainted surfaces from being marred due to the presence of dust particlestherein. At the same time the air in the booth is better conditioned forthe health and comfort of persons working therein, and the filter panelsmay last indefinitely, without need for replacement.

The air cleaning and conditioning unit of the invention is fullyportable and may be readily attached to and removed from a door, asdesired. It is applicable to the doors of existing paint booths as wellas those of new booths. The unit is characterized by its simplicity, andmay be manufactured at low cost.

The invention will be readily understood by referring to the followingdescription and the accompanying drawing, in which:

FIG. 1 is a perspective view showing a conventional two compartmentarrangement including a paint booth and a drying booth, for paintingautomobiles, arranged end to end, the booths having access doors attheir opposite ends and having other doors between them whereby anautomobile may be driven from one booth to the other, and having aforced draft ventilation system, including an exhaust fan, arrangedbetween the booths and communicating with the adjacent ends thereof,showing a pair of air cleaners embodying the invention as applied to twoof the doors of the paint booth; and

FIG. 2 is a sectional elevational view, on an enlarged scale, taken on amedian line, showing one of the paint booth doors and showing an aircleaner embodying the invention in its operative position relative tothe door.

Referring to FIG. 1 of the drawing, the numeral 1 designates generally aconventional two compartment arrangement which includes a paint booth 2and a drying booth 3, for painting automobiles, two of which areindicated by the numerals 4.

The paint booth 2 and the drying booth 3, which are arranged end to end,have access doors 5, 6 at their opposite ends and have other doors 7between them whereby an automobile 4 may be driven from one of thebooths 2, 3 to the other.

A forced draft ventilation system, which includes an exhaust fan 8, isarranged between the booths 2, 3 and communicates with the adjacent endsthereof.

As shown in FIG. 2, the doors 5 of the paint booth '2 have filterpanels, indicated generally by the numerals 9, through which atmosphericair is drawn into the paint booth 2, in the closed positions of thedoors 5, as by means of the exhaust fan 8. The combined area of thefilter panels 9 together approaches the area of the respective doors 5.

The structure abovedescribed is conventional, and is not claimed herein.

An air cleaning and conditioning unit embodying the invention,designated generally by the numeral 10, is applied to each of the doors5 of the paint booth 2, at the end of the booth 2 opposite the exhaustfan 8. The air cleaning and conditioning units 10 are applied to theoutside of the doors 5, in opposing relation to the filter panels 9 andin fluid communication therewith.

Referring now to FIG. 2 of the drawing, the air cleaning andconditioning unit 10, as hereinafter described, is fully portable andmay be readily attached .to and removed from a door, such as one of thedoors 5 of the paint booth 2, as desired. It is applicable to the doorsof existing paint booths as well as those of new booths. The unit 10 ischaracterized by its simplicity as well as its light weight andcompactness, and may be manufactured at low cost.

The air cleaning and conditioning unit includes a casing, indicatedgenerally by the numeral 11, which is generally rectangular andadvantageously may be formed of sheet metal. The casing 11 has heightand width dimensions somewhat greater than the corresponding dimensionsof the filter panels 9 together, which it overlies, and is comparativelythin, from front to back, relative to its width.

The casing 11, which is open at the back and has outwardly flangedperipheral edges, as at 12, whereby it is connected, by fasteningdevices 13, to marginal portions of the door 5 surrounding the filterpanels 9, has a top 14, a bottom 15, two opposite sides 16, and a pairof front panels 17, 18 which are positioned above and below a frontopening 19 as hereinafter described.

The front opening 19, which extends across the casing 11 and has avertical dimension substantially less than the corresponding dimensionof the filter panels 9 together, is positioned nearer the top 14 of thecasing 11 than the bottom 15 thereof, opposite the upper portions of thefilter panels 9.

The top 14 of the casing 11 is formed in part by a hinged cover,designated generally by the numeral 20, whereby the interior of thecasing 11 is readily accessible for cleaning.

A downwardly and rearwardly inclined baflle 21, which extends across thecasing 11 and is connected at its upper edge to the lower edge of theuppermost front panel 17, extends downwardly and rearwardly, inside thecasing 11, to a point below the upper edge of the lowermost front panel18 and rearwardly thereof, in spaced apart relation to the bottom 15.

A vertically extending baflie 22, which extends across the casing 11 andis spaced rearwardly of the inclined baffle 21, extends upwardly fromthe bottom 15, inside the casing 11, to a point above the lower edge ofthe uppermost front panel 17, in spaced apart relation to the top 14.

A series of oppositely inclined fins 23, 24, which extend across thecasing 11 and have their upper edges connected to the inclined baffle 21and the vertically extending baffle 22, respectively, are inclineddownwardly in mutually opposing, staggered relation to each other.

A downwardly and rearwardly inclined deflector member 25, which'iscomparatively short relative to the inclined baflle 21 and is positionedabove it, in rearwardly spaced, substantially parallel relation thereto,extends across the casing 11 and has its upper edge connected to the top14, rearwardly of the hinged cover20. The deflector member 25 extendsdownwardly and rearwardly to a point rearwardly of the verticallyextending baffle 22 and below its upper edge, between the verticallyextending baffle 22 and the filter panels 9.

A water reservoir is provided in the lower portion of the casing 11,between the lowermost front panel 18 and the vertically extending baifle22, as at 26. The water level in the reservoir 26 is spaced below thelower edge of the inclined bafiie 21.

The reservoir 26 may be filled with water, and the water level thereinmay be controlled either manually or automatically, by means not shown.Sight windows advantageously may be provided in the two opposite sides16 of the casing 11, as at 27, for use in observing the water level inthe reversoir 26.

In the operation of the air'cleaning and conditioning unit 10,atmospheric air is caused to flow through the unit 10, and thereafterinto the paint booth 2, through the filter panels 9 of the door 5, bythe action of the exhaust fan 8 as above described.

The incoming air does not flow directly, in a straight, horizontal path,through the unit 10, but is caused to change its direction of flowabruptly and repeatedly as it flows through the casing 11, and followsan indirect, generally zigzag course, downwardly between the inclinedbaflie 21 and the lowermost front panel 18, through the body of water inthe reservoir 26, upwardly between the inclined baflle 21 and thevertically extending baflle 22, over the several inclined fins 23, 24,and downwardly again between the vertically extending baflie 22 and thedeflector member 25.

In an optional arrangement, as shown, a small water trough 28, which hasa perforated bottom, extends along the lower edge of the inclined baflle21, and a strip of comparatively thin filter material, designated by thenumeral 29, which may consist of wire mesh, extends along the under sideof the water trough 28, below the perforations therein, and dependstherefrom.

The filter material 29 has one of its longitudinal edges connected tothe water trough 28, and extends from the under side of the water trough28 to a point immediately below the water level in the reservoir 26.

The water trough 28 is filled with water from the reservoir 26 by meansof a small pump 30, and the arrangement is such that a substantiallycontinuous sheet of water is caused to flow downwardly across the filtermaterial 29, and such portion of the incoming air as may bypass the bodyof water in the reservoir 25, as it changes its direction of flowadjacent the bottom of the casing 11, is subjected to a combined waterscrubbing and filtering action as it flows through the water wet filtermaterial 29.

The incoming air will also be cooled to some extent by the action of thewater in the reservoir 26, as above described, whereby the temperatureinside the booth 2 may be more pleasant in summer. A heater element (notshown) may be added for winter use, if desired.

The invention is not necessarily limited to an operation in which anexhaust fan, such as the exhaust fan 8, is relied on to draw atmosphericair into the booth 2. A suitable fan (not shown) may be added to theunit 10 if desired.

The invention may be modified in various ways without departing from thespirit and scope thereof.

I claim:

1. The combination of a spray booth, for painting automobiles and thelike, having a door, and having filter panels in the door wherebyatmospheric air drawn into the booth through the door, in the closedposition thereof;

may be substantially cleaned, the combined area of the filter panelsapproaching the area of the door, and a light Weight, compact aircleaning and conditioning unit rernovably connected to the outside ofthe door, in opposing relation to the filter panels and in fluidcommunication therewith, said unit being movable bodily with the doorupon opening and closing the door and consisting substantially in itsentirety of a casing, comparatively thin from front to back, overlyingthe filter panels, the casing being open at the back and having a frontopening spaced above the bottom thereof, oppositely extending bafiles inthe casing whereby air flowing through the casing is caused to followanindirect course, downwardly, and then upwardly, and downwardly again,a water reservoir in the bottom of the casing, below one of the baflles,in the path of air flowing downwardly and upwardly around said one ofthe baflles, a water trough having perforations in the bottom thereofextending along the lower edge of said one of the baflies, above thewater level in said reservoir and in spaced apart relation thereto, astrip of comparatively thin filter material having one of itslongitudinal edges connected to the under side of said trough, anddepending therefrom, below said perforations, said filter materialextending downwardly from said trough below said water level, and meansfor supplying water to said trough from said reservoir.

References Cited UNITED STATES PATENTS 10/1919 Wright et al.

(Other references on following page) Long 55-240 X Baker 55241 X Bingman55-229 X Hirs 55240 X Walton 55256 X 5 Rosenfeld.

Frankhauser 55256 X Sobeck 55259 X 6 FOREIGN PATENTS 12/ 1961 Australia.

4/ 1959 France. 2/1955 Great Britain.

HARRY B. THORNTON, Primary Examiner.

FRANK W. LUTTER, Examiner.

D. TALBERT, Assistant Examiner.

